1. Field of the Invention
The present invention relates to a door weather strip attached along a door frame of a motor vehicle for effecting a seal between a door opening of the motor vehicle and the door frame.
2. Description of the Prior Art
The door weather strip is generally provided with a base portion to be attached to an outer periphery of the door frame, and a tubular sealing portion projecting integrally from the base portion. When a door is closed, an inner side wall of the sealing portion is pressed to a body surface formed around the door opening to effect a seal between the door opening and the door frame.
In order to further improve the sealing performance between the door frame and the door opening, it is desirable to provide a double sealing construction. One example of the double sealing construction is shown in Japanese Utility Model Laid-open No. Sho 57-188520, wherein a bridge is formed so as to cross an inner cavity of the sealing portion for dividing it into an inside sealing portion and an outside sealing portion. When the door is closed, an inner side wall of the inside sealing portion is pressed to the body surface around the door opening while an upper wall of the outside sealing portion comes into contact with another body surface projecting along a roof side thereby effecting a double seal between the door opening and the door frame.
Meanwhile, during high speed running of a motor vehicle, an upper portion of the door is drawn outward to cause the decrease in sealing performance of the door weather strip. In order to overcome this problem, various means have been proposed, but these means are encountered by another problem that the construction becomes too complex.